A dental restoration is typically used to replace part of a natural tooth or even one or more entire natural teeth in a patient's mouth. A replacement of an entire tooth typically comprises a super structure, like a crown or a bridge, which typically is designed to resemble visible parts of a natural tooth. The tooth replacement typically further comprises a dental implant by which the replacement can be anchored in a patient's jaw. In many cases the super structure is connected to the dental implant via an abutment. Therefore such an abutment typically has an interface to the implant as well as a further interface to the super structure.
The dental implant is typically an elongated pin or screw which is inserted in a patient's jaw by surgery. After insertion the implant typically has to heal into the patient's jaw before the abutment and the super structure are placed on it. Typically the dental implant has a certain inclination angle in the patient's jaw to fit the anatomic situation in the patient's mouth, like for example the geometry of the gums and the jaw and their position relative to one another. On the other hand the super structure and/or the abutment may have to be angularly aligned to adjacent teeth so that the visible part of the final dental restoration is generally inline with such teeth. The angle required to fit with adjacent teeth may however be different from the angle of the implant. The abutment therefore may also provide for compensating such an angular offset.
To make the dental restoration fit nicely with adjacent teeth in a patient's mouth the abutment and/or the super structure is/are typically prepared by help of a physical model of the patient's teeth. Such a physical model typically also reproduces at least part of the inserted dental implant, for example an interface of the implant which is supposed to receive the abutment. Therefore a dental technician, for example, may physically shape and fit the abutment and/or the super structure into the desired place at the model.
The abutment and/or the super structure may also be prepared by using a CAD/CAM technique. In such a technique the shape of the physical model is typically captured by an optical measuring device. The so obtained computer model may then be used to design and manufacture the abutment and/or the super structure by computer aid. For the design of the abutment the shape of the implant interface is typically required in the form of computer data or a computer model. There are a variety of different implants on the market having dedicated uniquely shaped interfaces. Accordingly the implant manufacturers normally also provide computer models of at least the interfaces of their implants.
On the other hand in addition to the shape of the interface the actual position of the interface relative to other teeth in a patient's mouth is usually required to design the abutment and the super structure properly. For example the abutment and the super structure are usually designed to not only match with the interface of the implant, but also such that visible parts of the final dental restoration are positioned well inline with adjacent teeth.
In particular the inclination angle of the implant can typically not be provided by the implant manufacturer, but must be determined at the actual situation in a patient's mouth or at the physical model of the patient's teeth. To determine the inclination angle of the implant a measuring element is typically used. The measuring element is typically received on the interface of the implant and subsequently captured by the optical measuring device, like for example a three-dimensional scanner. The measuring element is typically shaped, for example elongated, such that its inclination angle can be determined from the captured shape. Some measuring elements also have a structure which indicates a rotational orientation, for example for use with implants having interfaces that require rotational positioning of the abutment to be received.
Because a measuring element must suit with a respective implant the implant manufacturers typically provide implant specific measuring elements.
Further the CAD software used to design the abutment and/or the super structure typically requires data about such a specific measuring element for recognizing the captured measuring element and for determining the angular position of the implant based thereon.
In summary the implant manufacturers typically have to provide data about the shape of the implant, data about the measuring element, and physical measure elements. On the other hand dental labs which use CAD/CAM methods for making tooth replacements based on several implant types typically purchase and maintain data libraries holding data about different implant types and measuring elements, and typically keep a stock holding a variety of physical measuring elements.
There are variations in the configuration of measuring elements, like one is disclosed in WO 2009/065954 A1. The document refers to a measuring body for an implant. The measuring body has a measuring geometry that can be captured by a measuring camera. Further the measuring body has a connection geometry for fitting on an implant. The measuring geometry and the connection geometry are separate parts. The same measuring geometry can be used with different connection geometries fitting different implants because the connection geometry and the measuring geometry have a unified interface with one another.
Although there are established approaches in the preparation of dental restorations there is still a need for facilitating the design of a dental restoration which is supposed to fit with a certain implant of a variety of different implants. It is further desirable to minimize the time period required to provide a dental restoration, and to provide a relatively inexpensive dental restoration that nevertheless has a relatively high quality.